Keywords:
Head and neck, Thyroid / Parathyroids, Ultrasound, Biopsy, Cancer
Authors:
P. Prieditis, M. Rauda, M. Tirane, K. Stepanovs, I. Štrumfa, M. Sperga, M. Radzina; Riga/LV
DOI:
10.1594/ecr2018/C-1878
Results
795 nodules were classified as TIRADS 2,
3,
4A,
4B and 5 in 14.5,
57.5,
14.2,
8.1,
5.7% of cases respectively.
Figure 1 shows cytology results and matched results of TIRADS categories.
Figure 2 shows TIRADS category 3 nodule echogenicity and cytology results.
Risk of malignancy were also calculated based on histology results.
For TIRADS categories 3 to 5 it was 17.7%,
45%,
58.3% and 76%,
respectively.
TIRADS category 2 had too small nodule count and one of them was lymphoma,
therefore risk of malignancy would not be statistical significant.
Since TIRADS category 3 risk of malignancy was slightly higher than the one calculated from cytology,
every TIRADS category 3 histologically malignant nodule were reconsidered and summary is reflected in Table 1.
We reviewed echogenicity of all 452 nodules in this category.
18 cases there were not possible to estimate nodule echogenicity because of USG image absence.
In other cases,
there were 37.2% isoechoic nodules.
52.2% hypoechoic nodules and 6.6% hyperechoic nodules.
Only one nodule in TIRADS group 3 had malignant result cytology and histology both and this nodule was hypoechoic.
Although cytology for these nodules were precise only in one case,
other cases are explainable – suspicious and follicular pathology cases requisite for operation in any case,
in two of three benign cases histology result were microfollicular carcinoma and one case – follicular variant of papillary carcinoma what is hard to detect.
There were no malignant or suspicious nodules in hyperechoic nodule group.
Calculated relative risk for isoechoic and hypoechoic nodule groups were 0.59 (95% CI 0.1164 - 2.9977) and 2.36 (95% CI 0.4651 - 11.9950),
respectively.
Although relative risk is slightly higher in hypoechoic nodule group,
overall it is low and this results are not statistically significant.
Therefore,
classification of simply hypoechoic nodules in higher risk group unnecessary raise FNA biopsy count and thereby cost of the patient and health care systems,
and,
also,
increase patient and clinician anxiety.
Table 1.
Summary of TIRADS category 3 malignant nodules in histology.
Nr. |
Bethesda category |
Histology result |
Echogenicity |
Remarks |
1. |
Follicular pathology |
Papillary carcinoma |
|
|
2. |
Follicular pathology |
Papillary carcinoma (follicular variant) |
Hypoechogenic |
|
3. |
Suspicious |
Papillary carcinoma |
Hypoechogenic |
|
4. |
Benign |
Microfollicular carcinoma |
Isoechogenic |
Hurthle cell carcinoma in other side |
5. |
Benign |
Papillary carcinoma (follicular variant) |
Isoechogenic |
|
6. |
Benign |
Microfollicular carcinoma |
Isoechogenic |
|
7. |
Malignant |
Papillary carcinoma (follicular variant) |
Hypoechogenic |
Multifocal |